SHINE: Solar Wind Magnetic Field Discontinuities and the Role of Alfvenic Turbulence

SHINE：太阳风磁场不连续性和阿尔芬湍流的作用

• 批准号: 0850705
• 负责人: Bernard Vasquez
• 金额: $ 18.13万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0850705&HistoricalAwards=false
• 关键词: SHINE; Solar; Wind; Magnetic; Field

The Principal Investigator (PI) will investigate the relationship between magnetic field discontinuities and the dissipation of turbulence in the solar wind, using a new method to accurately identify even small discontinuities in the solar wind. In a small preliminary study, this new method found numerous discontinuities with thicknesses consistent with ion kinetic scales, and these could be locations that dissipate the turbulent cascade energy. The PI will extend this initial study to all Advanced Composition Explorer (ACE) spacecraft data from March 1998 to the present, covering an entire solar activity cycle. The PI will evaluate the statistical properties of any discontinuities that are found and compare them to properties of turbulent fluctuations at the inertial dissipation range spectral break. He will also compare discontinuity frequency and other properties with local estimates of the turbulent cascade rate. This effort will help describe how small scale structures arise and contribute to heating the solar wind, as well as constrain the mechanisms responsible for the dissipation of turbulent fluctuations and the heating of ions in the solar wind near 1 AU. The PI's work will address fundamental physical processes that determine the development and evolution of the solar wind in the inner heliosphere and how small-scale processes in the solar wind couple to large-scale dynamics. This project is important for modeling the energization of the ambient solar wind through which coronal mass ejections (CMEs) must travel.Dissipation of the turbulent cascade is believed to be an important source of energizing the solar wind near Earth, and potentially from the corona to the outer heliosphere. The PI therefore expects this research to provide new approaches for magnetohydrodynamics (MHD) solar wind simulations and to enhance the accuracy of space weather forecasting. This research program will include the training and participation of both undergraduate and graduate students at University of New Hampshire.

首席研究员（PI）将研究磁场不连续性与太阳风中湍流消散之间的关系，使用一种新方法来准确识别太阳风中的微小不连续性。在一项小型初步研究中，这种新方法发现了许多厚度与离子动力学尺度一致的不连续性，这些不连续性可能是耗散湍流级联能量的位置。 PI 将把这项初步研究扩展到 1998 年 3 月至今的所有高级组合探测器 (ACE) 航天器数据，涵盖整个太阳活动周期。 PI 将评估所发现的任何不连续性的统计特性，并将其与惯性耗散范围光谱中断处的湍流波动特性进行比较。他还将不连续频率和其他属性与湍流级联速率的局部估计进行比较。这项工作将有助于描述小尺度结构如何产生并有助于加热太阳风，并限制负责湍流波动消散和太阳风中接近 1 个天文单位的离子加热的机制。 PI 的工作将解决决定日光层内太阳风的发展和演化的基本物理过程，以及太阳风中的小规模过程如何与大规模动态耦合。该项目对于模拟日冕物质抛射 (CME) 必须穿过的周围太阳风的激发非常重要。湍流级联的耗散被认为是地球附近太阳风激发的重要来源，并且可能从日冕到外日球层。因此，PI预计这项研究将为磁流体动力学（MHD）太阳风模拟提供新方法，并提高空间天气预报的准确性。该研究计划将包括新罕布什尔大学本科生和研究生的培训和参与。